basic java interview questions and answers

The first one discusses object-oriented programming and its features, common questions about Java and its functionality, Java collection classes, garbage collectors, this chapter focuses on exception handling, Java applets, SWING,JDBC, remote method Invocation (RMI), servlet, and JSP. Exception handling

class hello{public static void Main (string[] ARS) {A ab = new B (); Executed here, results: 1a2bAB = new B (); Executed here, results: 1a2b2b}}A: the output is 1a2b2b; the static code snippet for a class can be thought of as code executed by the class for the first load (virtual machine load), and for class loading, the first thing to do is to execute the construction of its base class, and then perform its own construction.50, the Succession time class execution order question, generally is t

example, a landing page, using the PO mode, will create a LoginPage class, the class will define the user name input box, password input box, login button webelenentFor the corresponding element to implement the corresponding method, the input box is used to input, you need to create a user name and enter the password method, so that the real page consistent, so the design concept is PO mode. The pagefactory belongs to the PO mode, which is used to initialize the page Class of each PO pattern i

This article was translated for the Silicon Valley Power website in 2002. At that time, xhtml1.0 was first introduced by designers, so there is a basic Q A below. The HTML language is a tool for us to build web pages. From its appearance to the present, the standards are constantly improved and the functions are getting stronger and stronger. However, there are still defects and deficiencies, and people are constantly improving it, making it easier t

class redefined the same method in the parent class. The Override method must have a method name, a parameter list, and a return type that are identical. The Override method does not restrict access to the original method.does 6.Java support multiple inheritance? Java does not support multiple inheritance, and each class allows only one class to be inherited, but multiple interfaces can be implemented.7. W

: This article mainly introduces the basic questions about PHP interview questions. if you are interested in PHP tutorials, please refer to them. 1. What methods do you use to solve the traffic issue for websites with large traffic volumes? First, check whether the server hardware is sufficient to support the current

finalize () method to sort system resources or perform other cleanup tasks. The finalize () method is called before the Garbage Collector deletes an object. 　Second, can anonymous inner class (anonymous internal class) be extends (inherited) other classes, or implements (implemented) interface (Interface )? An anonymous internal class is an internal class without a name. It cannot be extends (inherited) other classes, but an internal class can be used as an interface and implemented by another

multithreading problems include producer consumers, philosophers, readers, and simple bounded buffer. Knowing the basic concept of a thread is far from enough. You must know how to handle deadlocks, race conditions, memory conflicts, thread security, and other concurrency problems. With these skills, you can easily deal with multithreading and concurrent interviews.Many Java programmers will go to the

0x10 basic issues that embedded programmers should know C language testing is an essential and effective way to recruit embedded system programmers. Over the years, I have both participated in and organized many such tests. During this process, I realized that these tests could provide a lot of useful information for both the interviewer and the subject. Besides, I did not talk about the interview pressure,

Java Exception Handling interview questions, java exception handling questions 1. What are the differences between error and exception? An error indicates a system-level error. It is an internal error in the java Runtime Environme

some time ago because to participate in a written test, during the preparation of the online found two articles on the written topic, one of the In the process of finding these answers, I recorded the relevant answers and formed the following things. Need to explain that the following answer must have a lot of incomplete or even wrong place, need you to correct and perfect it, do not throw my eggs ah.I hope

, and the definition in the parent class is "masked". If multiple methods with the same name are defined in a class, either with a different number of parameters or with different parameter types, they are called overloads of the Method (overloading). The overloaded method can change the type of the return value. 19, the difference between integer and int int is the original data type of Java, and integer is the encapsulated class provided by

. TreeSetthe largest and smallest elements can be obtained from. Summary: Collections.sort() provides a list that is sorted once. PriorityQueueand TreeSet Dynamic maintenance of the ordered collection.9. Copy ListThere are two ways to copy a list. One is to use a ArrayList constructor. 1 ArrayListnewArrayList The other is to use Collections.copy() . 12 ArrayListnewArrayListCollections.copy(dstList, srcList); It is important to

establishes a dependency between the beans.Simply put, beans are objects that are initialized, assembled, and managed by the spring IOC container.The process of getting the Bean object, first loading the configuration file with resource and starting the IOC container, and then getting the bean object through the Getbean method, you can call his method.Scope of Spring Bean:There is only one shared bean instance in the Singleton:spring IOC container, which is generally the Singleton scope.Prototy

Java exception architecture diagram and several interview questions, java architecture diagram questions 1. java exception Architecture The pink ones are checked exceptions, which must be captured by the try {} catch Block or dec

Java basic interview (1) and java basic interview 1. When I use the final keyword to modify a variable, can the reference not be changed, or can the referenced variable not be changed? When you use the final keyword to modify a va

to Wangwei"$ Java-jar Blockchain-java-jar-with-dependencies.jar-add "Send 3.5 BTC to Wangwei"Print Blockchain$ Java-jar Blockchain-java-jar-with-dependencies.jar-printSummarizeIn this article we implement the Blockchain storage function, next we will implement the address, transaction, wallet, some of the functions of

10 classic Java interview questions and classic java questions 1. How does Java's HashMap work? HashMap is a key value for the data structure. Each key has a corresponding value. The key is to identify such a value. Based on the hashing principle, HashMap stores and obtain

Jame Dean 2016-12-06 17:12 Basic Knowledge section (90 points) one, the single choice question (altogether 12 questions, each question 3 points, altogether 36 points. ) 1, Java is from (B) language improvement redesign. A) Ada B) C + + C) pasacal D) BASIC 2. Which of the following statements is correct (B) A

Java interview questions, java questions1/** 2 * write a function. It accepts an integer (assuming length) and returns an array. The length of the array is length, 3 * the content in the array is a random value ranging from 0 to (length-1) and cannot be repeated. 4*5 * If the length is 5, the array may be [, 4]. 6*7 *